Recent advances in light projection technology and computer hardware are enabling the construction of large-format, high-resolution projector-based displays from groups of commodity light projectors and computers. These multi-projector displays create composite images on a display area from contributing images that are projected by the constituent projectors along different optical paths. In general, any overlap between the contributing images should be seamless in the composite images. To this end, the projectors of a multi-projector system are geometrically calibrated (or registered) to correct geometric misalignments across the projectors.
Various techniques have been developed for geometrically calibrating the projectors of multi-projector displays. In some geometric calibration approaches, one of more cameras provide feedback data relating to the images that are projected by the different projectors and projector calibration data is computed from the camera feedback data. The images projected by the projectors are geometrically aligned in accordance with the projector calibration data to generate seamless composite images.
In some approaches for calibrating multi-projector displays, correspondences across the different projectors are established manually or through the use of passive fiducial marks or through actively projecting detectable features (e.g., points or blobs). In other approaches, the geometric arrangement of the projectors and one or more cameras is precalibrated to derive a Euclidean frame of reference. Feedback from the one or more cameras is mapped onto the Euclidean frame of reference to generate a three-dimensional model in which the arrangement of the projectors, the one or more cameras, and the display area are expressed within a single three-dimensional coordinate system (i.e., a world coordinate system). The three-dimensional model is used to prewarp the contributing images so that the projected images appear geometrically registered and undistorted on the display area.